How do I find the area of an unknown triangle

Players on the school soccer team are selling candles to raise money for an upcoming trip. each player has 24 candles to sell. if a player sells 4 candles a profit of$30 is made. if he sells 12 candles a profit of $70 is made

If i have 20$ and i gave 5$ away how much i got

What is the solution to the system of equation graphed belowa.(0,-4)b.(2,5),1),-3)